As the demand for more fuel-efficient and quieter aircraft increases, aero structures are becoming more advanced and a demand for aerofoils with larger surface area but smaller cross-sectional height is apparent. As a result, the limitations of conventional attachment structures and fixings used to couple sections of an aerofoil to each other have been reached or exceeded because of the restricted area of contact between wing sections resulting in a lack of space for conventional fixings which is exacerbated by regulations that restricts the minimum spacing between fixing holes. It is also apparent that conventional fixings are not always able to withstand the high level of stresses placed upon them when they are used with such new and developing wing geometries.
An aerofoil having two sections is described with reference to the Applicant's own earlier application GB200919019 filed on 30 Oct. 2009. The outboard section is able to rotate about a hinge shaft set at a compound angle relative to a longitudinal axis extending along the length of the wing and a chordal axis extending at ninety-degrees to the longitudinal axis, so that the outboard section assumes a stowed, substantial vertical, position when the aircraft is not in flight, thereby enabling the aircraft to have a much longer wingspan than is normal but at the same time achieving the practicalities of an aircraft with a shorter wingspan in terms of being able to use a standard airport gate.
It has now been appreciated that the wing geometry and compound hinge arrangement known from the aforementioned earlier application can also be used in applications where two aerofoil structures are to be coupled together, even in aircraft with a conventional wingspan and where there is no intention of rotating one aerofoil structure relative to the other aerofoil structure when the aircraft is not in flight but in which the aerofoil structures are to remain in their relative positions subsequent to assembly and on a permanent basis until or unless they are taken apart for maintenance or repair. This method of assembly of adjacent wing structures particularly lends itself to aero structures of larger surface area but lower cross-sectional height, where the use of conventional fixings is problematic for the reasons already explained above. No method of assembling adjacent aero structures is disclosed in WO 2011/051699 which, in any event, describes a complex gear mechanism for controlling movement of one aero structure relative to the other aero structure and which is not required in the method of the present invention, as relative movement of the aero structures is not required following final assembly.